As has been demonstrated (page 51), the consideration of possible physical objectives (in space) is essential to the selection of suitable objectives (in mind). Moreover, action with reference to one or more physical objectives is the necessary basis for determining the feasibility and acceptability of a plan. Military objectives can be achieved only through the application of power, actually or by threat (page 8), with reference to physical objectives. The determination of correct physical objectives is followed, if more than one such objective is found, by the selection of the one or more which are best adapted to the requirements of the situation. The procedure for determination and for selection is a matter for painstaking mental effort, based on the considerations now to be presented. The term "military objective" is frequently used in military literature to distinguish physical objectives which are combatant in character from those which are noncombatant. The considerations which follow are applicable to physical objectives of all categories. Procedure for Determination and Selection of Correct Physical Objectives. In a particular set of circumstances, the field wherein correct physical objectives may be found and the best selected, is that of an existent or probable theater of action. The determination of a physical objective, when correct, initially satisfies the requirement of suitability with respect to the nature of the objective,--this being, in such case, the appropriate effect desired (page 31). Physical objectives not suitable, with relation to the objective to be attained, are manifestly incorrect physical points of orientation with respect to the operations involved in the effort to attain such an objective. It may be found, however, that the selection of a single physical objective will not fulfill this requirement. A commander may find it necessary to direct his effort simultaneously, or in succession, with relation to more than one physical objective. When a succession of physical objectives has to be dealt with, the selection will necessarily include such a series. Such a case might occur where a campaign has been found necessary in the form of successive stages as essential features. The visualized termination of each successive stage may be marked by the successful application of effort with respect to one or more physical objectives. Such a series of physical objectives may frequently also occur in operations on a smaller scale; even in very minor actions such a succession of efforts is normal. (See page 54, as to objectives.)